Is there a pecking order in which include files must be listed in the declarations? Or is including those files similar to sourcing files in shell scripts and the order is (most of the time) unimportant?
Well, new #includes should go under existing ones within their respective blocks, unless that would cause a build failure.
Typically, system defines are in the first block, then TQt defines in the next block, then Trinity defines in the next, the finally any local includes (the includes in this last block are in quotes, not angle brackets). Note that this is specific to the Trinity project and is merely a style preference.
Tim